5,370 research outputs found
Distribution functions for a family of axially symmetric galaxy models
We present the derivation of distribution functions for the first four
members of a family of disks, previously obtained in (MNRAS, 371, 1873, 2006),
which represent a family of axially symmetric galaxy models with finite radius
and well behaved surface mass density. In order to do this we employ several
approaches that have been developed starting from the potential-density pair
and, essentially using the method introduced by Kalnajs (Ap. J., 205, 751,
1976) we obtain some distribution functions that depend on the Jacobi integral.
Now, as this method demands that the mass density can be properly expressed as
a function of the gravitational potential, we can do this only for the first
four discs of the family. We also find another kind of distribution functions
by starting with the even part of the previous distribution functions and using
the maximum entropy principle in order to find the odd part and so a new
distribution function, as it was pointed out by Dejonghe (Phys. Rep., 133, 217,
1986). The result is a wide variety of equilibrium states corresponding to
several self-consistent finite flat galaxy models.Comment: 12 pages, 7 figures, updated version, accepted for publication in
Rev. Acad. Colomb. Cienc. Ex. Fis. Na
Application of a Natural Language Interface to the Teleoperation of a Mobile Robot
IFAC Intelligent Components for Vehicles, Seville, Spain, 1998This paper describes the application of a natural language interface to the teleoperation of a mobile robot. Natural language communication with robots is a major goal, since it allows for non expert people to communicate with robots in his or her own language. This communication has to be flexible enough to allow the user to control the robot with a minimum knowledge about its details. In order to do this, the user must be able to perform simple operations as well as high level tasks which involve multiple elements of the system. For this ones, an adequate representation of the knowledge about the robot and its environment will allow the creation of a plan of simple actions whose execution will result in the accomplishment of the requested tas
La transformación del Estado del bienestar desde la óptica municipal: breve estudio comparado del gobierno y la administración local
[Resumen:] La lógica de funcionamiento actual de acuerdo con el principio económico ha obligado
a reflexionar sobre el estudio de las estructuras tradicionales sobre las que se asienta el Estado y,
en particular, sobre aquellas que, entendemos, deben servir para recuperar la credibilidad de las
instituciones políticas públicas, es decir, las entidades locales, cuya proximidad con el ciudadano las
coloca en un lugar privilegiado para esta finalidad. Se ha aproximado el estudio desde una perspectiva
comparada tratando de ofrecer referencias para su utilización en la adopción de estrategias de análisis
sobre la evolución y reforma de la administración local.[Abstract:] The current logic operation according to the economic principle has forced reflect on
the study of traditional structures on which the government rests, and in particular on those that
we believe should be used to restore the credibility of political institutions, the local authorities,
whose proximity to the city places them in a privileged place for this purpose. It has been estimated
from a comparative study trying to provide references for use in decision analysis strategies on the
development and reform of local government perspective
Development and Experimental Validation of a Dynamic Model for a Fresnel Solar Collector
this paper presents a lumped parameter dynamic model of a Fresnel collector field
of a solar refrigeration plant. The plant is located in the Escuela Superior de Ingenieros of the
University of Seville. The dynamic model parameter model developed can be used as a control
model or as a simulation tool to test controllers. The lumped parameters have been determined
by using real data from the plant in different operating conditions. The model has been validated
against a data validation set obtained from the plant. The model has shown to reproduce the
system behavior with a good compromise in accuracy and model complexity
Hexavalent Chromium Removal by a Paecilomyces sp. Fungal Strain Isolated from Environment
A resistant and capable fungal strain in removing hexavalent chromium was isolated from an environment near of Chemical Science Faculty, located in the city of San Luis Potosí, Mexico. The strain was identified as Paecilomyces sp., by macro- and microscopic characteristics. Strain resistance of the strain to high Cr (VI) concentrations and its ability to reduce chromium were studied. When it was incubated in minimal medium with glucose, another inexpensive commercial carbon source like unrefined and brown sugar or glycerol, in the presence of 50 mg/L of Cr (VI), the strain caused complete disappearance of Cr (VI), with the concomitant production of Cr (III) in the growth medium after 7 days of incubation, at 28°C, pH 4.0, 100 rpm, and an inoculum of 38 mg of dry weight. Decrease of Cr (VI) levels from industrial wastes was also induced by Paecilomyces biomass. These results indicate that reducing capacity of chromate resistant filamentous fungus Cr (VI) could be useful for the removal of Cr (VI) pollution
Editor's Note
The international conference “Disruptive Technologies Tech Ethics and Artificial Intelligence” (DITTET) provides a forum to present and discuss the latest scientific and technical advances and their implications in the field of ethics. It also provides a forum for experts to present their latest research in disruptive technologies, promoting knowledge transfer. It provides a unique opportunity to bring together experts in different fields, academics, and professionals to exchange their experience in the development and deployment of disruptive technologies, artificial intelligence, and their ethical problems.
This Special Issue contains extended versions of selected works presented at the 1st International Conference on Disruptive Technologies, Tech Ethics and Artificial Intelligence (DiTTEt 2021), held in Salamanca (Spain) in September 2021
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